You are being scheduled to undergo an ablation procedure to treat your atrial fibrillation. Complications of ablation procedures include damage to structures near the heart from the heat energy used during the ablation procedure. These complications include damage to the esophagus (the tube through which food passes when you swallow) and stomach. A rare but often fatal complication resulting from severe heat damage is called an atrio-esophageal fistula (an abnormal connection between the heart and esophagus). However, the frequency of minimal damage to the esophagus or nerves of the gut that may go unnoticed are not known.

This study is designed to determine how often atrial fibrillation ablation causes problems with the stomach and esophagus.

Inclusion criteria:

• All patients aged 18 years or more who undergo pulmonary vein isolation with radiofrequency ablation for clinically indicated atrial fibrillation.

Exclusion criteria:

1. Patients with established diagnosis of esophageal or gastric function abnormalities.
2. Patients who are unable to give consent or major psychiatric condition not under control.
3. Patients who had abdominal surgical procedures on stomach, esophagus or pancreas (Esophagectomy, Gastrostomy, Gastrectomy (Billroth I, Billroth II, Roux-en-Y), Bariatric surgery [Gastric bypass surgery, Adjustable gastric band, Sleeve gastrectomy, Vertical banded gastroplasty surgery], Gastroenterostomy, Hill repair, Nissen fundoplication, Gastropexy, Pancreatectomy, Pancreaticoduodenectomy, Pancreas transplantation, vagotomy).
4. Patients who unable to undergo any of the above mentioned procedures namely, esophageal manometry or sham feeding test or scientigraphy gastric emptying scan.
5. Patients with chronic pancreatitis.
6. Patients with either acute or chronic neuropathies such as diabetic, inflammatory, autoimmune and cranial neuropathies effecting vagal nerve or gastroparesis or achalasia. Limited peripheral neuropathies such as carpal tunnel syndrome or isolated Bell's palsy can be included.
7. Patients who have undergone previous radiofrequency ablation for atrial fibrillation or patients who had history of either minimally invasive or invasive or maze or modified maze procedures for atrial fibrillation.

If you agree to participate in the study, you will undergo a series of tests about a week before the expected ablation procedure. The same tests will be repeated 24-48 hours after the ablation. These tests include esophageal manometry, gastric emptying scan, sham feeding test and completing a symptoms questionnaire.